pH-Zone-Refining Countercurrent Chromatography

Methodology for optimally sized centrifugal partition chromatography columns

“…Main developments of the separation process were on the solvent choice for biphasic system selection [4,5], on new separation methods (pH zone refining [6]; or ion exchange which are displacement chromatography modes [7]) or new application fields [8][9][10]. In the two past decades, technological improvements lead to new CPC apparatuses.…”

An efficient and target-oriented sample enrichment method for preparative separation of minor alkaloids by pH-zone-refining counter-current chromatography

“…The greatest advantage of the separation technique is its large sample loading capacity, which exceeds 10-fold than that of conventional CCC in the same separation column [6]. But it was required that the sample should contain a sufficient amount of target components and must be completely soluble or making a fine homogeneous suspension in the stationary phase containing retainer and a lesser amount of the mobile phase free of the eluter [9]. Otherwise the separation superiority of pHzone-refining CCC will not be brought to full play.…”

Overcoming the equivalent-chain-length rule with pH-zone-refining countercurrent chromatography for the preparative separation of fatty acids

“…Ionizable analytes interact with the solvent system in terms of protonation and de-protonation which results in differing solubilities and partitioning behaviors of the neutral and ionized forms [17]. During isocratic elution, contiguous and rectangularly shaped peaks (pH-zones) are formed-each depending on the acid strength (pK a value) and hydrophobicity of the inherent analyte [22]. The involvement of both factors during the separation process appeared to offer a way to circumvent the co-elutions pursuant to the limitations in FA separations caused by the ECL rule.…”